v4.19.13 snapshot.
diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c
new file mode 100644
index 0000000..02ad03a
--- /dev/null
+++ b/drivers/net/ppp/ppp_generic.c
@@ -0,0 +1,3289 @@
+/*
+ * Generic PPP layer for Linux.
+ *
+ * Copyright 1999-2002 Paul Mackerras.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * The generic PPP layer handles the PPP network interfaces, the
+ * /dev/ppp device, packet and VJ compression, and multilink.
+ * It talks to PPP `channels' via the interface defined in
+ * include/linux/ppp_channel.h. Channels provide the basic means for
+ * sending and receiving PPP frames on some kind of communications
+ * channel.
+ *
+ * Part of the code in this driver was inspired by the old async-only
+ * PPP driver, written by Michael Callahan and Al Longyear, and
+ * subsequently hacked by Paul Mackerras.
+ *
+ * ==FILEVERSION 20041108==
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/sched/signal.h>
+#include <linux/kmod.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/idr.h>
+#include <linux/netdevice.h>
+#include <linux/poll.h>
+#include <linux/ppp_defs.h>
+#include <linux/filter.h>
+#include <linux/ppp-ioctl.h>
+#include <linux/ppp_channel.h>
+#include <linux/ppp-comp.h>
+#include <linux/skbuff.h>
+#include <linux/rtnetlink.h>
+#include <linux/if_arp.h>
+#include <linux/ip.h>
+#include <linux/tcp.h>
+#include <linux/spinlock.h>
+#include <linux/rwsem.h>
+#include <linux/stddef.h>
+#include <linux/device.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/file.h>
+#include <asm/unaligned.h>
+#include <net/slhc_vj.h>
+#include <linux/atomic.h>
+#include <linux/refcount.h>
+
+#include <linux/nsproxy.h>
+#include <net/net_namespace.h>
+#include <net/netns/generic.h>
+
+#define PPP_VERSION "2.4.2"
+
+/*
+ * Network protocols we support.
+ */
+#define NP_IP 0 /* Internet Protocol V4 */
+#define NP_IPV6 1 /* Internet Protocol V6 */
+#define NP_IPX 2 /* IPX protocol */
+#define NP_AT 3 /* Appletalk protocol */
+#define NP_MPLS_UC 4 /* MPLS unicast */
+#define NP_MPLS_MC 5 /* MPLS multicast */
+#define NUM_NP 6 /* Number of NPs. */
+
+#define MPHDRLEN 6 /* multilink protocol header length */
+#define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
+
+/*
+ * An instance of /dev/ppp can be associated with either a ppp
+ * interface unit or a ppp channel. In both cases, file->private_data
+ * points to one of these.
+ */
+struct ppp_file {
+ enum {
+ INTERFACE=1, CHANNEL
+ } kind;
+ struct sk_buff_head xq; /* pppd transmit queue */
+ struct sk_buff_head rq; /* receive queue for pppd */
+ wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
+ refcount_t refcnt; /* # refs (incl /dev/ppp attached) */
+ int hdrlen; /* space to leave for headers */
+ int index; /* interface unit / channel number */
+ int dead; /* unit/channel has been shut down */
+};
+
+#define PF_TO_X(pf, X) container_of(pf, X, file)
+
+#define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
+#define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
+
+/*
+ * Data structure to hold primary network stats for which
+ * we want to use 64 bit storage. Other network stats
+ * are stored in dev->stats of the ppp strucute.
+ */
+struct ppp_link_stats {
+ u64 rx_packets;
+ u64 tx_packets;
+ u64 rx_bytes;
+ u64 tx_bytes;
+};
+
+/*
+ * Data structure describing one ppp unit.
+ * A ppp unit corresponds to a ppp network interface device
+ * and represents a multilink bundle.
+ * It can have 0 or more ppp channels connected to it.
+ */
+struct ppp {
+ struct ppp_file file; /* stuff for read/write/poll 0 */
+ struct file *owner; /* file that owns this unit 48 */
+ struct list_head channels; /* list of attached channels 4c */
+ int n_channels; /* how many channels are attached 54 */
+ spinlock_t rlock; /* lock for receive side 58 */
+ spinlock_t wlock; /* lock for transmit side 5c */
+ int __percpu *xmit_recursion; /* xmit recursion detect */
+ int mru; /* max receive unit 60 */
+ unsigned int flags; /* control bits 64 */
+ unsigned int xstate; /* transmit state bits 68 */
+ unsigned int rstate; /* receive state bits 6c */
+ int debug; /* debug flags 70 */
+ struct slcompress *vj; /* state for VJ header compression */
+ enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
+ struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
+ struct compressor *xcomp; /* transmit packet compressor 8c */
+ void *xc_state; /* its internal state 90 */
+ struct compressor *rcomp; /* receive decompressor 94 */
+ void *rc_state; /* its internal state 98 */
+ unsigned long last_xmit; /* jiffies when last pkt sent 9c */
+ unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
+ struct net_device *dev; /* network interface device a4 */
+ int closing; /* is device closing down? a8 */
+#ifdef CONFIG_PPP_MULTILINK
+ int nxchan; /* next channel to send something on */
+ u32 nxseq; /* next sequence number to send */
+ int mrru; /* MP: max reconst. receive unit */
+ u32 nextseq; /* MP: seq no of next packet */
+ u32 minseq; /* MP: min of most recent seqnos */
+ struct sk_buff_head mrq; /* MP: receive reconstruction queue */
+#endif /* CONFIG_PPP_MULTILINK */
+#ifdef CONFIG_PPP_FILTER
+ struct bpf_prog *pass_filter; /* filter for packets to pass */
+ struct bpf_prog *active_filter; /* filter for pkts to reset idle */
+#endif /* CONFIG_PPP_FILTER */
+ struct net *ppp_net; /* the net we belong to */
+ struct ppp_link_stats stats64; /* 64 bit network stats */
+};
+
+/*
+ * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
+ * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
+ * SC_MUST_COMP
+ * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
+ * Bits in xstate: SC_COMP_RUN
+ */
+#define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
+ |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
+ |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
+
+/*
+ * Private data structure for each channel.
+ * This includes the data structure used for multilink.
+ */
+struct channel {
+ struct ppp_file file; /* stuff for read/write/poll */
+ struct list_head list; /* link in all/new_channels list */
+ struct ppp_channel *chan; /* public channel data structure */
+ struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
+ spinlock_t downl; /* protects `chan', file.xq dequeue */
+ struct ppp *ppp; /* ppp unit we're connected to */
+ struct net *chan_net; /* the net channel belongs to */
+ struct list_head clist; /* link in list of channels per unit */
+ rwlock_t upl; /* protects `ppp' */
+#ifdef CONFIG_PPP_MULTILINK
+ u8 avail; /* flag used in multilink stuff */
+ u8 had_frag; /* >= 1 fragments have been sent */
+ u32 lastseq; /* MP: last sequence # received */
+ int speed; /* speed of the corresponding ppp channel*/
+#endif /* CONFIG_PPP_MULTILINK */
+};
+
+struct ppp_config {
+ struct file *file;
+ s32 unit;
+ bool ifname_is_set;
+};
+
+/*
+ * SMP locking issues:
+ * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
+ * list and the ppp.n_channels field, you need to take both locks
+ * before you modify them.
+ * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
+ * channel.downl.
+ */
+
+static DEFINE_MUTEX(ppp_mutex);
+static atomic_t ppp_unit_count = ATOMIC_INIT(0);
+static atomic_t channel_count = ATOMIC_INIT(0);
+
+/* per-net private data for this module */
+static unsigned int ppp_net_id __read_mostly;
+struct ppp_net {
+ /* units to ppp mapping */
+ struct idr units_idr;
+
+ /*
+ * all_ppp_mutex protects the units_idr mapping.
+ * It also ensures that finding a ppp unit in the units_idr
+ * map and updating its file.refcnt field is atomic.
+ */
+ struct mutex all_ppp_mutex;
+
+ /* channels */
+ struct list_head all_channels;
+ struct list_head new_channels;
+ int last_channel_index;
+
+ /*
+ * all_channels_lock protects all_channels and
+ * last_channel_index, and the atomicity of find
+ * a channel and updating its file.refcnt field.
+ */
+ spinlock_t all_channels_lock;
+};
+
+/* Get the PPP protocol number from a skb */
+#define PPP_PROTO(skb) get_unaligned_be16((skb)->data)
+
+/* We limit the length of ppp->file.rq to this (arbitrary) value */
+#define PPP_MAX_RQLEN 32
+
+/*
+ * Maximum number of multilink fragments queued up.
+ * This has to be large enough to cope with the maximum latency of
+ * the slowest channel relative to the others. Strictly it should
+ * depend on the number of channels and their characteristics.
+ */
+#define PPP_MP_MAX_QLEN 128
+
+/* Multilink header bits. */
+#define B 0x80 /* this fragment begins a packet */
+#define E 0x40 /* this fragment ends a packet */
+
+/* Compare multilink sequence numbers (assumed to be 32 bits wide) */
+#define seq_before(a, b) ((s32)((a) - (b)) < 0)
+#define seq_after(a, b) ((s32)((a) - (b)) > 0)
+
+/* Prototypes. */
+static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
+ struct file *file, unsigned int cmd, unsigned long arg);
+static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb);
+static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
+static void ppp_push(struct ppp *ppp);
+static void ppp_channel_push(struct channel *pch);
+static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
+ struct channel *pch);
+static void ppp_receive_error(struct ppp *ppp);
+static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
+static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
+ struct sk_buff *skb);
+#ifdef CONFIG_PPP_MULTILINK
+static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
+ struct channel *pch);
+static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
+static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
+static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
+#endif /* CONFIG_PPP_MULTILINK */
+static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
+static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
+static void ppp_ccp_closed(struct ppp *ppp);
+static struct compressor *find_compressor(int type);
+static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
+static int ppp_create_interface(struct net *net, struct file *file, int *unit);
+static void init_ppp_file(struct ppp_file *pf, int kind);
+static void ppp_destroy_interface(struct ppp *ppp);
+static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit);
+static struct channel *ppp_find_channel(struct ppp_net *pn, int unit);
+static int ppp_connect_channel(struct channel *pch, int unit);
+static int ppp_disconnect_channel(struct channel *pch);
+static void ppp_destroy_channel(struct channel *pch);
+static int unit_get(struct idr *p, void *ptr);
+static int unit_set(struct idr *p, void *ptr, int n);
+static void unit_put(struct idr *p, int n);
+static void *unit_find(struct idr *p, int n);
+static void ppp_setup(struct net_device *dev);
+
+static const struct net_device_ops ppp_netdev_ops;
+
+static struct class *ppp_class;
+
+/* per net-namespace data */
+static inline struct ppp_net *ppp_pernet(struct net *net)
+{
+ BUG_ON(!net);
+
+ return net_generic(net, ppp_net_id);
+}
+
+/* Translates a PPP protocol number to a NP index (NP == network protocol) */
+static inline int proto_to_npindex(int proto)
+{
+ switch (proto) {
+ case PPP_IP:
+ return NP_IP;
+ case PPP_IPV6:
+ return NP_IPV6;
+ case PPP_IPX:
+ return NP_IPX;
+ case PPP_AT:
+ return NP_AT;
+ case PPP_MPLS_UC:
+ return NP_MPLS_UC;
+ case PPP_MPLS_MC:
+ return NP_MPLS_MC;
+ }
+ return -EINVAL;
+}
+
+/* Translates an NP index into a PPP protocol number */
+static const int npindex_to_proto[NUM_NP] = {
+ PPP_IP,
+ PPP_IPV6,
+ PPP_IPX,
+ PPP_AT,
+ PPP_MPLS_UC,
+ PPP_MPLS_MC,
+};
+
+/* Translates an ethertype into an NP index */
+static inline int ethertype_to_npindex(int ethertype)
+{
+ switch (ethertype) {
+ case ETH_P_IP:
+ return NP_IP;
+ case ETH_P_IPV6:
+ return NP_IPV6;
+ case ETH_P_IPX:
+ return NP_IPX;
+ case ETH_P_PPPTALK:
+ case ETH_P_ATALK:
+ return NP_AT;
+ case ETH_P_MPLS_UC:
+ return NP_MPLS_UC;
+ case ETH_P_MPLS_MC:
+ return NP_MPLS_MC;
+ }
+ return -1;
+}
+
+/* Translates an NP index into an ethertype */
+static const int npindex_to_ethertype[NUM_NP] = {
+ ETH_P_IP,
+ ETH_P_IPV6,
+ ETH_P_IPX,
+ ETH_P_PPPTALK,
+ ETH_P_MPLS_UC,
+ ETH_P_MPLS_MC,
+};
+
+/*
+ * Locking shorthand.
+ */
+#define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
+#define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
+#define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
+#define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
+#define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
+ ppp_recv_lock(ppp); } while (0)
+#define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
+ ppp_xmit_unlock(ppp); } while (0)
+
+/*
+ * /dev/ppp device routines.
+ * The /dev/ppp device is used by pppd to control the ppp unit.
+ * It supports the read, write, ioctl and poll functions.
+ * Open instances of /dev/ppp can be in one of three states:
+ * unattached, attached to a ppp unit, or attached to a ppp channel.
+ */
+static int ppp_open(struct inode *inode, struct file *file)
+{
+ /*
+ * This could (should?) be enforced by the permissions on /dev/ppp.
+ */
+ if (!ns_capable(file->f_cred->user_ns, CAP_NET_ADMIN))
+ return -EPERM;
+ return 0;
+}
+
+static int ppp_release(struct inode *unused, struct file *file)
+{
+ struct ppp_file *pf = file->private_data;
+ struct ppp *ppp;
+
+ if (pf) {
+ file->private_data = NULL;
+ if (pf->kind == INTERFACE) {
+ ppp = PF_TO_PPP(pf);
+ rtnl_lock();
+ if (file == ppp->owner)
+ unregister_netdevice(ppp->dev);
+ rtnl_unlock();
+ }
+ if (refcount_dec_and_test(&pf->refcnt)) {
+ switch (pf->kind) {
+ case INTERFACE:
+ ppp_destroy_interface(PF_TO_PPP(pf));
+ break;
+ case CHANNEL:
+ ppp_destroy_channel(PF_TO_CHANNEL(pf));
+ break;
+ }
+ }
+ }
+ return 0;
+}
+
+static ssize_t ppp_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct ppp_file *pf = file->private_data;
+ DECLARE_WAITQUEUE(wait, current);
+ ssize_t ret;
+ struct sk_buff *skb = NULL;
+ struct iovec iov;
+ struct iov_iter to;
+
+ ret = count;
+
+ if (!pf)
+ return -ENXIO;
+ add_wait_queue(&pf->rwait, &wait);
+ for (;;) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ skb = skb_dequeue(&pf->rq);
+ if (skb)
+ break;
+ ret = 0;
+ if (pf->dead)
+ break;
+ if (pf->kind == INTERFACE) {
+ /*
+ * Return 0 (EOF) on an interface that has no
+ * channels connected, unless it is looping
+ * network traffic (demand mode).
+ */
+ struct ppp *ppp = PF_TO_PPP(pf);
+
+ ppp_recv_lock(ppp);
+ if (ppp->n_channels == 0 &&
+ (ppp->flags & SC_LOOP_TRAFFIC) == 0) {
+ ppp_recv_unlock(ppp);
+ break;
+ }
+ ppp_recv_unlock(ppp);
+ }
+ ret = -EAGAIN;
+ if (file->f_flags & O_NONBLOCK)
+ break;
+ ret = -ERESTARTSYS;
+ if (signal_pending(current))
+ break;
+ schedule();
+ }
+ set_current_state(TASK_RUNNING);
+ remove_wait_queue(&pf->rwait, &wait);
+
+ if (!skb)
+ goto out;
+
+ ret = -EOVERFLOW;
+ if (skb->len > count)
+ goto outf;
+ ret = -EFAULT;
+ iov.iov_base = buf;
+ iov.iov_len = count;
+ iov_iter_init(&to, READ, &iov, 1, count);
+ if (skb_copy_datagram_iter(skb, 0, &to, skb->len))
+ goto outf;
+ ret = skb->len;
+
+ outf:
+ kfree_skb(skb);
+ out:
+ return ret;
+}
+
+static ssize_t ppp_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct ppp_file *pf = file->private_data;
+ struct sk_buff *skb;
+ ssize_t ret;
+
+ if (!pf)
+ return -ENXIO;
+ ret = -ENOMEM;
+ skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
+ if (!skb)
+ goto out;
+ skb_reserve(skb, pf->hdrlen);
+ ret = -EFAULT;
+ if (copy_from_user(skb_put(skb, count), buf, count)) {
+ kfree_skb(skb);
+ goto out;
+ }
+
+ switch (pf->kind) {
+ case INTERFACE:
+ ppp_xmit_process(PF_TO_PPP(pf), skb);
+ break;
+ case CHANNEL:
+ skb_queue_tail(&pf->xq, skb);
+ ppp_channel_push(PF_TO_CHANNEL(pf));
+ break;
+ }
+
+ ret = count;
+
+ out:
+ return ret;
+}
+
+/* No kernel lock - fine */
+static __poll_t ppp_poll(struct file *file, poll_table *wait)
+{
+ struct ppp_file *pf = file->private_data;
+ __poll_t mask;
+
+ if (!pf)
+ return 0;
+ poll_wait(file, &pf->rwait, wait);
+ mask = EPOLLOUT | EPOLLWRNORM;
+ if (skb_peek(&pf->rq))
+ mask |= EPOLLIN | EPOLLRDNORM;
+ if (pf->dead)
+ mask |= EPOLLHUP;
+ else if (pf->kind == INTERFACE) {
+ /* see comment in ppp_read */
+ struct ppp *ppp = PF_TO_PPP(pf);
+
+ ppp_recv_lock(ppp);
+ if (ppp->n_channels == 0 &&
+ (ppp->flags & SC_LOOP_TRAFFIC) == 0)
+ mask |= EPOLLIN | EPOLLRDNORM;
+ ppp_recv_unlock(ppp);
+ }
+
+ return mask;
+}
+
+#ifdef CONFIG_PPP_FILTER
+static int get_filter(void __user *arg, struct sock_filter **p)
+{
+ struct sock_fprog uprog;
+ struct sock_filter *code = NULL;
+ int len;
+
+ if (copy_from_user(&uprog, arg, sizeof(uprog)))
+ return -EFAULT;
+
+ if (!uprog.len) {
+ *p = NULL;
+ return 0;
+ }
+
+ len = uprog.len * sizeof(struct sock_filter);
+ code = memdup_user(uprog.filter, len);
+ if (IS_ERR(code))
+ return PTR_ERR(code);
+
+ *p = code;
+ return uprog.len;
+}
+#endif /* CONFIG_PPP_FILTER */
+
+static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ struct ppp_file *pf;
+ struct ppp *ppp;
+ int err = -EFAULT, val, val2, i;
+ struct ppp_idle idle;
+ struct npioctl npi;
+ int unit, cflags;
+ struct slcompress *vj;
+ void __user *argp = (void __user *)arg;
+ int __user *p = argp;
+
+ mutex_lock(&ppp_mutex);
+
+ pf = file->private_data;
+ if (!pf) {
+ err = ppp_unattached_ioctl(current->nsproxy->net_ns,
+ pf, file, cmd, arg);
+ goto out;
+ }
+
+ if (cmd == PPPIOCDETACH) {
+ /*
+ * PPPIOCDETACH is no longer supported as it was heavily broken,
+ * and is only known to have been used by pppd older than
+ * ppp-2.4.2 (released November 2003).
+ */
+ pr_warn_once("%s (%d) used obsolete PPPIOCDETACH ioctl\n",
+ current->comm, current->pid);
+ err = -EINVAL;
+ goto out;
+ }
+
+ if (pf->kind == CHANNEL) {
+ struct channel *pch;
+ struct ppp_channel *chan;
+
+ pch = PF_TO_CHANNEL(pf);
+
+ switch (cmd) {
+ case PPPIOCCONNECT:
+ if (get_user(unit, p))
+ break;
+ err = ppp_connect_channel(pch, unit);
+ break;
+
+ case PPPIOCDISCONN:
+ err = ppp_disconnect_channel(pch);
+ break;
+
+ default:
+ down_read(&pch->chan_sem);
+ chan = pch->chan;
+ err = -ENOTTY;
+ if (chan && chan->ops->ioctl)
+ err = chan->ops->ioctl(chan, cmd, arg);
+ up_read(&pch->chan_sem);
+ }
+ goto out;
+ }
+
+ if (pf->kind != INTERFACE) {
+ /* can't happen */
+ pr_err("PPP: not interface or channel??\n");
+ err = -EINVAL;
+ goto out;
+ }
+
+ ppp = PF_TO_PPP(pf);
+ switch (cmd) {
+ case PPPIOCSMRU:
+ if (get_user(val, p))
+ break;
+ ppp->mru = val;
+ err = 0;
+ break;
+
+ case PPPIOCSFLAGS:
+ if (get_user(val, p))
+ break;
+ ppp_lock(ppp);
+ cflags = ppp->flags & ~val;
+#ifdef CONFIG_PPP_MULTILINK
+ if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK))
+ ppp->nextseq = 0;
+#endif
+ ppp->flags = val & SC_FLAG_BITS;
+ ppp_unlock(ppp);
+ if (cflags & SC_CCP_OPEN)
+ ppp_ccp_closed(ppp);
+ err = 0;
+ break;
+
+ case PPPIOCGFLAGS:
+ val = ppp->flags | ppp->xstate | ppp->rstate;
+ if (put_user(val, p))
+ break;
+ err = 0;
+ break;
+
+ case PPPIOCSCOMPRESS:
+ err = ppp_set_compress(ppp, arg);
+ break;
+
+ case PPPIOCGUNIT:
+ if (put_user(ppp->file.index, p))
+ break;
+ err = 0;
+ break;
+
+ case PPPIOCSDEBUG:
+ if (get_user(val, p))
+ break;
+ ppp->debug = val;
+ err = 0;
+ break;
+
+ case PPPIOCGDEBUG:
+ if (put_user(ppp->debug, p))
+ break;
+ err = 0;
+ break;
+
+ case PPPIOCGIDLE:
+ idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
+ idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
+ if (copy_to_user(argp, &idle, sizeof(idle)))
+ break;
+ err = 0;
+ break;
+
+ case PPPIOCSMAXCID:
+ if (get_user(val, p))
+ break;
+ val2 = 15;
+ if ((val >> 16) != 0) {
+ val2 = val >> 16;
+ val &= 0xffff;
+ }
+ vj = slhc_init(val2+1, val+1);
+ if (IS_ERR(vj)) {
+ err = PTR_ERR(vj);
+ break;
+ }
+ ppp_lock(ppp);
+ if (ppp->vj)
+ slhc_free(ppp->vj);
+ ppp->vj = vj;
+ ppp_unlock(ppp);
+ err = 0;
+ break;
+
+ case PPPIOCGNPMODE:
+ case PPPIOCSNPMODE:
+ if (copy_from_user(&npi, argp, sizeof(npi)))
+ break;
+ err = proto_to_npindex(npi.protocol);
+ if (err < 0)
+ break;
+ i = err;
+ if (cmd == PPPIOCGNPMODE) {
+ err = -EFAULT;
+ npi.mode = ppp->npmode[i];
+ if (copy_to_user(argp, &npi, sizeof(npi)))
+ break;
+ } else {
+ ppp->npmode[i] = npi.mode;
+ /* we may be able to transmit more packets now (??) */
+ netif_wake_queue(ppp->dev);
+ }
+ err = 0;
+ break;
+
+#ifdef CONFIG_PPP_FILTER
+ case PPPIOCSPASS:
+ {
+ struct sock_filter *code;
+
+ err = get_filter(argp, &code);
+ if (err >= 0) {
+ struct bpf_prog *pass_filter = NULL;
+ struct sock_fprog_kern fprog = {
+ .len = err,
+ .filter = code,
+ };
+
+ err = 0;
+ if (fprog.filter)
+ err = bpf_prog_create(&pass_filter, &fprog);
+ if (!err) {
+ ppp_lock(ppp);
+ if (ppp->pass_filter)
+ bpf_prog_destroy(ppp->pass_filter);
+ ppp->pass_filter = pass_filter;
+ ppp_unlock(ppp);
+ }
+ kfree(code);
+ }
+ break;
+ }
+ case PPPIOCSACTIVE:
+ {
+ struct sock_filter *code;
+
+ err = get_filter(argp, &code);
+ if (err >= 0) {
+ struct bpf_prog *active_filter = NULL;
+ struct sock_fprog_kern fprog = {
+ .len = err,
+ .filter = code,
+ };
+
+ err = 0;
+ if (fprog.filter)
+ err = bpf_prog_create(&active_filter, &fprog);
+ if (!err) {
+ ppp_lock(ppp);
+ if (ppp->active_filter)
+ bpf_prog_destroy(ppp->active_filter);
+ ppp->active_filter = active_filter;
+ ppp_unlock(ppp);
+ }
+ kfree(code);
+ }
+ break;
+ }
+#endif /* CONFIG_PPP_FILTER */
+
+#ifdef CONFIG_PPP_MULTILINK
+ case PPPIOCSMRRU:
+ if (get_user(val, p))
+ break;
+ ppp_recv_lock(ppp);
+ ppp->mrru = val;
+ ppp_recv_unlock(ppp);
+ err = 0;
+ break;
+#endif /* CONFIG_PPP_MULTILINK */
+
+ default:
+ err = -ENOTTY;
+ }
+
+out:
+ mutex_unlock(&ppp_mutex);
+
+ return err;
+}
+
+static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
+ struct file *file, unsigned int cmd, unsigned long arg)
+{
+ int unit, err = -EFAULT;
+ struct ppp *ppp;
+ struct channel *chan;
+ struct ppp_net *pn;
+ int __user *p = (int __user *)arg;
+
+ switch (cmd) {
+ case PPPIOCNEWUNIT:
+ /* Create a new ppp unit */
+ if (get_user(unit, p))
+ break;
+ err = ppp_create_interface(net, file, &unit);
+ if (err < 0)
+ break;
+
+ err = -EFAULT;
+ if (put_user(unit, p))
+ break;
+ err = 0;
+ break;
+
+ case PPPIOCATTACH:
+ /* Attach to an existing ppp unit */
+ if (get_user(unit, p))
+ break;
+ err = -ENXIO;
+ pn = ppp_pernet(net);
+ mutex_lock(&pn->all_ppp_mutex);
+ ppp = ppp_find_unit(pn, unit);
+ if (ppp) {
+ refcount_inc(&ppp->file.refcnt);
+ file->private_data = &ppp->file;
+ err = 0;
+ }
+ mutex_unlock(&pn->all_ppp_mutex);
+ break;
+
+ case PPPIOCATTCHAN:
+ if (get_user(unit, p))
+ break;
+ err = -ENXIO;
+ pn = ppp_pernet(net);
+ spin_lock_bh(&pn->all_channels_lock);
+ chan = ppp_find_channel(pn, unit);
+ if (chan) {
+ refcount_inc(&chan->file.refcnt);
+ file->private_data = &chan->file;
+ err = 0;
+ }
+ spin_unlock_bh(&pn->all_channels_lock);
+ break;
+
+ default:
+ err = -ENOTTY;
+ }
+
+ return err;
+}
+
+static const struct file_operations ppp_device_fops = {
+ .owner = THIS_MODULE,
+ .read = ppp_read,
+ .write = ppp_write,
+ .poll = ppp_poll,
+ .unlocked_ioctl = ppp_ioctl,
+ .open = ppp_open,
+ .release = ppp_release,
+ .llseek = noop_llseek,
+};
+
+static __net_init int ppp_init_net(struct net *net)
+{
+ struct ppp_net *pn = net_generic(net, ppp_net_id);
+
+ idr_init(&pn->units_idr);
+ mutex_init(&pn->all_ppp_mutex);
+
+ INIT_LIST_HEAD(&pn->all_channels);
+ INIT_LIST_HEAD(&pn->new_channels);
+
+ spin_lock_init(&pn->all_channels_lock);
+
+ return 0;
+}
+
+static __net_exit void ppp_exit_net(struct net *net)
+{
+ struct ppp_net *pn = net_generic(net, ppp_net_id);
+ struct net_device *dev;
+ struct net_device *aux;
+ struct ppp *ppp;
+ LIST_HEAD(list);
+ int id;
+
+ rtnl_lock();
+ for_each_netdev_safe(net, dev, aux) {
+ if (dev->netdev_ops == &ppp_netdev_ops)
+ unregister_netdevice_queue(dev, &list);
+ }
+
+ idr_for_each_entry(&pn->units_idr, ppp, id)
+ /* Skip devices already unregistered by previous loop */
+ if (!net_eq(dev_net(ppp->dev), net))
+ unregister_netdevice_queue(ppp->dev, &list);
+
+ unregister_netdevice_many(&list);
+ rtnl_unlock();
+
+ mutex_destroy(&pn->all_ppp_mutex);
+ idr_destroy(&pn->units_idr);
+ WARN_ON_ONCE(!list_empty(&pn->all_channels));
+ WARN_ON_ONCE(!list_empty(&pn->new_channels));
+}
+
+static struct pernet_operations ppp_net_ops = {
+ .init = ppp_init_net,
+ .exit = ppp_exit_net,
+ .id = &ppp_net_id,
+ .size = sizeof(struct ppp_net),
+};
+
+static int ppp_unit_register(struct ppp *ppp, int unit, bool ifname_is_set)
+{
+ struct ppp_net *pn = ppp_pernet(ppp->ppp_net);
+ int ret;
+
+ mutex_lock(&pn->all_ppp_mutex);
+
+ if (unit < 0) {
+ ret = unit_get(&pn->units_idr, ppp);
+ if (ret < 0)
+ goto err;
+ } else {
+ /* Caller asked for a specific unit number. Fail with -EEXIST
+ * if unavailable. For backward compatibility, return -EEXIST
+ * too if idr allocation fails; this makes pppd retry without
+ * requesting a specific unit number.
+ */
+ if (unit_find(&pn->units_idr, unit)) {
+ ret = -EEXIST;
+ goto err;
+ }
+ ret = unit_set(&pn->units_idr, ppp, unit);
+ if (ret < 0) {
+ /* Rewrite error for backward compatibility */
+ ret = -EEXIST;
+ goto err;
+ }
+ }
+ ppp->file.index = ret;
+
+ if (!ifname_is_set)
+ snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ppp->file.index);
+
+ mutex_unlock(&pn->all_ppp_mutex);
+
+ ret = register_netdevice(ppp->dev);
+ if (ret < 0)
+ goto err_unit;
+
+ atomic_inc(&ppp_unit_count);
+
+ return 0;
+
+err_unit:
+ mutex_lock(&pn->all_ppp_mutex);
+ unit_put(&pn->units_idr, ppp->file.index);
+err:
+ mutex_unlock(&pn->all_ppp_mutex);
+
+ return ret;
+}
+
+static int ppp_dev_configure(struct net *src_net, struct net_device *dev,
+ const struct ppp_config *conf)
+{
+ struct ppp *ppp = netdev_priv(dev);
+ int indx;
+ int err;
+ int cpu;
+
+ ppp->dev = dev;
+ ppp->ppp_net = src_net;
+ ppp->mru = PPP_MRU;
+ ppp->owner = conf->file;
+
+ init_ppp_file(&ppp->file, INTERFACE);
+ ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
+
+ for (indx = 0; indx < NUM_NP; ++indx)
+ ppp->npmode[indx] = NPMODE_PASS;
+ INIT_LIST_HEAD(&ppp->channels);
+ spin_lock_init(&ppp->rlock);
+ spin_lock_init(&ppp->wlock);
+
+ ppp->xmit_recursion = alloc_percpu(int);
+ if (!ppp->xmit_recursion) {
+ err = -ENOMEM;
+ goto err1;
+ }
+ for_each_possible_cpu(cpu)
+ (*per_cpu_ptr(ppp->xmit_recursion, cpu)) = 0;
+
+#ifdef CONFIG_PPP_MULTILINK
+ ppp->minseq = -1;
+ skb_queue_head_init(&ppp->mrq);
+#endif /* CONFIG_PPP_MULTILINK */
+#ifdef CONFIG_PPP_FILTER
+ ppp->pass_filter = NULL;
+ ppp->active_filter = NULL;
+#endif /* CONFIG_PPP_FILTER */
+
+ err = ppp_unit_register(ppp, conf->unit, conf->ifname_is_set);
+ if (err < 0)
+ goto err2;
+
+ conf->file->private_data = &ppp->file;
+
+ return 0;
+err2:
+ free_percpu(ppp->xmit_recursion);
+err1:
+ return err;
+}
+
+static const struct nla_policy ppp_nl_policy[IFLA_PPP_MAX + 1] = {
+ [IFLA_PPP_DEV_FD] = { .type = NLA_S32 },
+};
+
+static int ppp_nl_validate(struct nlattr *tb[], struct nlattr *data[],
+ struct netlink_ext_ack *extack)
+{
+ if (!data)
+ return -EINVAL;
+
+ if (!data[IFLA_PPP_DEV_FD])
+ return -EINVAL;
+ if (nla_get_s32(data[IFLA_PPP_DEV_FD]) < 0)
+ return -EBADF;
+
+ return 0;
+}
+
+static int ppp_nl_newlink(struct net *src_net, struct net_device *dev,
+ struct nlattr *tb[], struct nlattr *data[],
+ struct netlink_ext_ack *extack)
+{
+ struct ppp_config conf = {
+ .unit = -1,
+ .ifname_is_set = true,
+ };
+ struct file *file;
+ int err;
+
+ file = fget(nla_get_s32(data[IFLA_PPP_DEV_FD]));
+ if (!file)
+ return -EBADF;
+
+ /* rtnl_lock is already held here, but ppp_create_interface() locks
+ * ppp_mutex before holding rtnl_lock. Using mutex_trylock() avoids
+ * possible deadlock due to lock order inversion, at the cost of
+ * pushing the problem back to userspace.
+ */
+ if (!mutex_trylock(&ppp_mutex)) {
+ err = -EBUSY;
+ goto out;
+ }
+
+ if (file->f_op != &ppp_device_fops || file->private_data) {
+ err = -EBADF;
+ goto out_unlock;
+ }
+
+ conf.file = file;
+
+ /* Don't use device name generated by the rtnetlink layer when ifname
+ * isn't specified. Let ppp_dev_configure() set the device name using
+ * the PPP unit identifer as suffix (i.e. ppp<unit_id>). This allows
+ * userspace to infer the device name using to the PPPIOCGUNIT ioctl.
+ */
+ if (!tb[IFLA_IFNAME])
+ conf.ifname_is_set = false;
+
+ err = ppp_dev_configure(src_net, dev, &conf);
+
+out_unlock:
+ mutex_unlock(&ppp_mutex);
+out:
+ fput(file);
+
+ return err;
+}
+
+static void ppp_nl_dellink(struct net_device *dev, struct list_head *head)
+{
+ unregister_netdevice_queue(dev, head);
+}
+
+static size_t ppp_nl_get_size(const struct net_device *dev)
+{
+ return 0;
+}
+
+static int ppp_nl_fill_info(struct sk_buff *skb, const struct net_device *dev)
+{
+ return 0;
+}
+
+static struct net *ppp_nl_get_link_net(const struct net_device *dev)
+{
+ struct ppp *ppp = netdev_priv(dev);
+
+ return ppp->ppp_net;
+}
+
+static struct rtnl_link_ops ppp_link_ops __read_mostly = {
+ .kind = "ppp",
+ .maxtype = IFLA_PPP_MAX,
+ .policy = ppp_nl_policy,
+ .priv_size = sizeof(struct ppp),
+ .setup = ppp_setup,
+ .validate = ppp_nl_validate,
+ .newlink = ppp_nl_newlink,
+ .dellink = ppp_nl_dellink,
+ .get_size = ppp_nl_get_size,
+ .fill_info = ppp_nl_fill_info,
+ .get_link_net = ppp_nl_get_link_net,
+};
+
+#define PPP_MAJOR 108
+
+/* Called at boot time if ppp is compiled into the kernel,
+ or at module load time (from init_module) if compiled as a module. */
+static int __init ppp_init(void)
+{
+ int err;
+
+ pr_info("PPP generic driver version " PPP_VERSION "\n");
+
+ err = register_pernet_device(&ppp_net_ops);
+ if (err) {
+ pr_err("failed to register PPP pernet device (%d)\n", err);
+ goto out;
+ }
+
+ err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
+ if (err) {
+ pr_err("failed to register PPP device (%d)\n", err);
+ goto out_net;
+ }
+
+ ppp_class = class_create(THIS_MODULE, "ppp");
+ if (IS_ERR(ppp_class)) {
+ err = PTR_ERR(ppp_class);
+ goto out_chrdev;
+ }
+
+ err = rtnl_link_register(&ppp_link_ops);
+ if (err) {
+ pr_err("failed to register rtnetlink PPP handler\n");
+ goto out_class;
+ }
+
+ /* not a big deal if we fail here :-) */
+ device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
+
+ return 0;
+
+out_class:
+ class_destroy(ppp_class);
+out_chrdev:
+ unregister_chrdev(PPP_MAJOR, "ppp");
+out_net:
+ unregister_pernet_device(&ppp_net_ops);
+out:
+ return err;
+}
+
+/*
+ * Network interface unit routines.
+ */
+static netdev_tx_t
+ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ struct ppp *ppp = netdev_priv(dev);
+ int npi, proto;
+ unsigned char *pp;
+
+ npi = ethertype_to_npindex(ntohs(skb->protocol));
+ if (npi < 0)
+ goto outf;
+
+ /* Drop, accept or reject the packet */
+ switch (ppp->npmode[npi]) {
+ case NPMODE_PASS:
+ break;
+ case NPMODE_QUEUE:
+ /* it would be nice to have a way to tell the network
+ system to queue this one up for later. */
+ goto outf;
+ case NPMODE_DROP:
+ case NPMODE_ERROR:
+ goto outf;
+ }
+
+ /* Put the 2-byte PPP protocol number on the front,
+ making sure there is room for the address and control fields. */
+ if (skb_cow_head(skb, PPP_HDRLEN))
+ goto outf;
+
+ pp = skb_push(skb, 2);
+ proto = npindex_to_proto[npi];
+ put_unaligned_be16(proto, pp);
+
+ skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev)));
+ ppp_xmit_process(ppp, skb);
+
+ return NETDEV_TX_OK;
+
+ outf:
+ kfree_skb(skb);
+ ++dev->stats.tx_dropped;
+ return NETDEV_TX_OK;
+}
+
+static int
+ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
+{
+ struct ppp *ppp = netdev_priv(dev);
+ int err = -EFAULT;
+ void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
+ struct ppp_stats stats;
+ struct ppp_comp_stats cstats;
+ char *vers;
+
+ switch (cmd) {
+ case SIOCGPPPSTATS:
+ ppp_get_stats(ppp, &stats);
+ if (copy_to_user(addr, &stats, sizeof(stats)))
+ break;
+ err = 0;
+ break;
+
+ case SIOCGPPPCSTATS:
+ memset(&cstats, 0, sizeof(cstats));
+ if (ppp->xc_state)
+ ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
+ if (ppp->rc_state)
+ ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
+ if (copy_to_user(addr, &cstats, sizeof(cstats)))
+ break;
+ err = 0;
+ break;
+
+ case SIOCGPPPVER:
+ vers = PPP_VERSION;
+ if (copy_to_user(addr, vers, strlen(vers) + 1))
+ break;
+ err = 0;
+ break;
+
+ default:
+ err = -EINVAL;
+ }
+
+ return err;
+}
+
+static void
+ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64)
+{
+ struct ppp *ppp = netdev_priv(dev);
+
+ ppp_recv_lock(ppp);
+ stats64->rx_packets = ppp->stats64.rx_packets;
+ stats64->rx_bytes = ppp->stats64.rx_bytes;
+ ppp_recv_unlock(ppp);
+
+ ppp_xmit_lock(ppp);
+ stats64->tx_packets = ppp->stats64.tx_packets;
+ stats64->tx_bytes = ppp->stats64.tx_bytes;
+ ppp_xmit_unlock(ppp);
+
+ stats64->rx_errors = dev->stats.rx_errors;
+ stats64->tx_errors = dev->stats.tx_errors;
+ stats64->rx_dropped = dev->stats.rx_dropped;
+ stats64->tx_dropped = dev->stats.tx_dropped;
+ stats64->rx_length_errors = dev->stats.rx_length_errors;
+}
+
+static int ppp_dev_init(struct net_device *dev)
+{
+ struct ppp *ppp;
+
+ netdev_lockdep_set_classes(dev);
+
+ ppp = netdev_priv(dev);
+ /* Let the netdevice take a reference on the ppp file. This ensures
+ * that ppp_destroy_interface() won't run before the device gets
+ * unregistered.
+ */
+ refcount_inc(&ppp->file.refcnt);
+
+ return 0;
+}
+
+static void ppp_dev_uninit(struct net_device *dev)
+{
+ struct ppp *ppp = netdev_priv(dev);
+ struct ppp_net *pn = ppp_pernet(ppp->ppp_net);
+
+ ppp_lock(ppp);
+ ppp->closing = 1;
+ ppp_unlock(ppp);
+
+ mutex_lock(&pn->all_ppp_mutex);
+ unit_put(&pn->units_idr, ppp->file.index);
+ mutex_unlock(&pn->all_ppp_mutex);
+
+ ppp->owner = NULL;
+
+ ppp->file.dead = 1;
+ wake_up_interruptible(&ppp->file.rwait);
+}
+
+static void ppp_dev_priv_destructor(struct net_device *dev)
+{
+ struct ppp *ppp;
+
+ ppp = netdev_priv(dev);
+ if (refcount_dec_and_test(&ppp->file.refcnt))
+ ppp_destroy_interface(ppp);
+}
+
+static const struct net_device_ops ppp_netdev_ops = {
+ .ndo_init = ppp_dev_init,
+ .ndo_uninit = ppp_dev_uninit,
+ .ndo_start_xmit = ppp_start_xmit,
+ .ndo_do_ioctl = ppp_net_ioctl,
+ .ndo_get_stats64 = ppp_get_stats64,
+};
+
+static struct device_type ppp_type = {
+ .name = "ppp",
+};
+
+static void ppp_setup(struct net_device *dev)
+{
+ dev->netdev_ops = &ppp_netdev_ops;
+ SET_NETDEV_DEVTYPE(dev, &ppp_type);
+
+ dev->features |= NETIF_F_LLTX;
+
+ dev->hard_header_len = PPP_HDRLEN;
+ dev->mtu = PPP_MRU;
+ dev->addr_len = 0;
+ dev->tx_queue_len = 3;
+ dev->type = ARPHRD_PPP;
+ dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
+ dev->priv_destructor = ppp_dev_priv_destructor;
+ netif_keep_dst(dev);
+}
+
+/*
+ * Transmit-side routines.
+ */
+
+/* Called to do any work queued up on the transmit side that can now be done */
+static void __ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb)
+{
+ ppp_xmit_lock(ppp);
+ if (!ppp->closing) {
+ ppp_push(ppp);
+
+ if (skb)
+ skb_queue_tail(&ppp->file.xq, skb);
+ while (!ppp->xmit_pending &&
+ (skb = skb_dequeue(&ppp->file.xq)))
+ ppp_send_frame(ppp, skb);
+ /* If there's no work left to do, tell the core net
+ code that we can accept some more. */
+ if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
+ netif_wake_queue(ppp->dev);
+ else
+ netif_stop_queue(ppp->dev);
+ }
+ ppp_xmit_unlock(ppp);
+}
+
+static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb)
+{
+ local_bh_disable();
+
+ if (unlikely(*this_cpu_ptr(ppp->xmit_recursion)))
+ goto err;
+
+ (*this_cpu_ptr(ppp->xmit_recursion))++;
+ __ppp_xmit_process(ppp, skb);
+ (*this_cpu_ptr(ppp->xmit_recursion))--;
+
+ local_bh_enable();
+
+ return;
+
+err:
+ local_bh_enable();
+
+ kfree_skb(skb);
+
+ if (net_ratelimit())
+ netdev_err(ppp->dev, "recursion detected\n");
+}
+
+static inline struct sk_buff *
+pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
+{
+ struct sk_buff *new_skb;
+ int len;
+ int new_skb_size = ppp->dev->mtu +
+ ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
+ int compressor_skb_size = ppp->dev->mtu +
+ ppp->xcomp->comp_extra + PPP_HDRLEN;
+ new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
+ if (!new_skb) {
+ if (net_ratelimit())
+ netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n");
+ return NULL;
+ }
+ if (ppp->dev->hard_header_len > PPP_HDRLEN)
+ skb_reserve(new_skb,
+ ppp->dev->hard_header_len - PPP_HDRLEN);
+
+ /* compressor still expects A/C bytes in hdr */
+ len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
+ new_skb->data, skb->len + 2,
+ compressor_skb_size);
+ if (len > 0 && (ppp->flags & SC_CCP_UP)) {
+ consume_skb(skb);
+ skb = new_skb;
+ skb_put(skb, len);
+ skb_pull(skb, 2); /* pull off A/C bytes */
+ } else if (len == 0) {
+ /* didn't compress, or CCP not up yet */
+ consume_skb(new_skb);
+ new_skb = skb;
+ } else {
+ /*
+ * (len < 0)
+ * MPPE requires that we do not send unencrypted
+ * frames. The compressor will return -1 if we
+ * should drop the frame. We cannot simply test
+ * the compress_proto because MPPE and MPPC share
+ * the same number.
+ */
+ if (net_ratelimit())
+ netdev_err(ppp->dev, "ppp: compressor dropped pkt\n");
+ kfree_skb(skb);
+ consume_skb(new_skb);
+ new_skb = NULL;
+ }
+ return new_skb;
+}
+
+/*
+ * Compress and send a frame.
+ * The caller should have locked the xmit path,
+ * and xmit_pending should be 0.
+ */
+static void
+ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
+{
+ int proto = PPP_PROTO(skb);
+ struct sk_buff *new_skb;
+ int len;
+ unsigned char *cp;
+
+ if (proto < 0x8000) {
+#ifdef CONFIG_PPP_FILTER
+ /* check if we should pass this packet */
+ /* the filter instructions are constructed assuming
+ a four-byte PPP header on each packet */
+ *(u8 *)skb_push(skb, 2) = 1;
+ if (ppp->pass_filter &&
+ BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
+ if (ppp->debug & 1)
+ netdev_printk(KERN_DEBUG, ppp->dev,
+ "PPP: outbound frame "
+ "not passed\n");
+ kfree_skb(skb);
+ return;
+ }
+ /* if this packet passes the active filter, record the time */
+ if (!(ppp->active_filter &&
+ BPF_PROG_RUN(ppp->active_filter, skb) == 0))
+ ppp->last_xmit = jiffies;
+ skb_pull(skb, 2);
+#else
+ /* for data packets, record the time */
+ ppp->last_xmit = jiffies;
+#endif /* CONFIG_PPP_FILTER */
+ }
+
+ ++ppp->stats64.tx_packets;
+ ppp->stats64.tx_bytes += skb->len - 2;
+
+ switch (proto) {
+ case PPP_IP:
+ if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
+ break;
+ /* try to do VJ TCP header compression */
+ new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
+ GFP_ATOMIC);
+ if (!new_skb) {
+ netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n");
+ goto drop;
+ }
+ skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
+ cp = skb->data + 2;
+ len = slhc_compress(ppp->vj, cp, skb->len - 2,
+ new_skb->data + 2, &cp,
+ !(ppp->flags & SC_NO_TCP_CCID));
+ if (cp == skb->data + 2) {
+ /* didn't compress */
+ consume_skb(new_skb);
+ } else {
+ if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
+ proto = PPP_VJC_COMP;
+ cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
+ } else {
+ proto = PPP_VJC_UNCOMP;
+ cp[0] = skb->data[2];
+ }
+ consume_skb(skb);
+ skb = new_skb;
+ cp = skb_put(skb, len + 2);
+ cp[0] = 0;
+ cp[1] = proto;
+ }
+ break;
+
+ case PPP_CCP:
+ /* peek at outbound CCP frames */
+ ppp_ccp_peek(ppp, skb, 0);
+ break;
+ }
+
+ /* try to do packet compression */
+ if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state &&
+ proto != PPP_LCP && proto != PPP_CCP) {
+ if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
+ if (net_ratelimit())
+ netdev_err(ppp->dev,
+ "ppp: compression required but "
+ "down - pkt dropped.\n");
+ goto drop;
+ }
+ skb = pad_compress_skb(ppp, skb);
+ if (!skb)
+ goto drop;
+ }
+
+ /*
+ * If we are waiting for traffic (demand dialling),
+ * queue it up for pppd to receive.
+ */
+ if (ppp->flags & SC_LOOP_TRAFFIC) {
+ if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
+ goto drop;
+ skb_queue_tail(&ppp->file.rq, skb);
+ wake_up_interruptible(&ppp->file.rwait);
+ return;
+ }
+
+ ppp->xmit_pending = skb;
+ ppp_push(ppp);
+ return;
+
+ drop:
+ kfree_skb(skb);
+ ++ppp->dev->stats.tx_errors;
+}
+
+/*
+ * Try to send the frame in xmit_pending.
+ * The caller should have the xmit path locked.
+ */
+static void
+ppp_push(struct ppp *ppp)
+{
+ struct list_head *list;
+ struct channel *pch;
+ struct sk_buff *skb = ppp->xmit_pending;
+
+ if (!skb)
+ return;
+
+ list = &ppp->channels;
+ if (list_empty(list)) {
+ /* nowhere to send the packet, just drop it */
+ ppp->xmit_pending = NULL;
+ kfree_skb(skb);
+ return;
+ }
+
+ if ((ppp->flags & SC_MULTILINK) == 0) {
+ /* not doing multilink: send it down the first channel */
+ list = list->next;
+ pch = list_entry(list, struct channel, clist);
+
+ spin_lock(&pch->downl);
+ if (pch->chan) {
+ if (pch->chan->ops->start_xmit(pch->chan, skb))
+ ppp->xmit_pending = NULL;
+ } else {
+ /* channel got unregistered */
+ kfree_skb(skb);
+ ppp->xmit_pending = NULL;
+ }
+ spin_unlock(&pch->downl);
+ return;
+ }
+
+#ifdef CONFIG_PPP_MULTILINK
+ /* Multilink: fragment the packet over as many links
+ as can take the packet at the moment. */
+ if (!ppp_mp_explode(ppp, skb))
+ return;
+#endif /* CONFIG_PPP_MULTILINK */
+
+ ppp->xmit_pending = NULL;
+ kfree_skb(skb);
+}
+
+#ifdef CONFIG_PPP_MULTILINK
+static bool mp_protocol_compress __read_mostly = true;
+module_param(mp_protocol_compress, bool, 0644);
+MODULE_PARM_DESC(mp_protocol_compress,
+ "compress protocol id in multilink fragments");
+
+/*
+ * Divide a packet to be transmitted into fragments and
+ * send them out the individual links.
+ */
+static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
+{
+ int len, totlen;
+ int i, bits, hdrlen, mtu;
+ int flen;
+ int navail, nfree, nzero;
+ int nbigger;
+ int totspeed;
+ int totfree;
+ unsigned char *p, *q;
+ struct list_head *list;
+ struct channel *pch;
+ struct sk_buff *frag;
+ struct ppp_channel *chan;
+
+ totspeed = 0; /*total bitrate of the bundle*/
+ nfree = 0; /* # channels which have no packet already queued */
+ navail = 0; /* total # of usable channels (not deregistered) */
+ nzero = 0; /* number of channels with zero speed associated*/
+ totfree = 0; /*total # of channels available and
+ *having no queued packets before
+ *starting the fragmentation*/
+
+ hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
+ i = 0;
+ list_for_each_entry(pch, &ppp->channels, clist) {
+ if (pch->chan) {
+ pch->avail = 1;
+ navail++;
+ pch->speed = pch->chan->speed;
+ } else {
+ pch->avail = 0;
+ }
+ if (pch->avail) {
+ if (skb_queue_empty(&pch->file.xq) ||
+ !pch->had_frag) {
+ if (pch->speed == 0)
+ nzero++;
+ else
+ totspeed += pch->speed;
+
+ pch->avail = 2;
+ ++nfree;
+ ++totfree;
+ }
+ if (!pch->had_frag && i < ppp->nxchan)
+ ppp->nxchan = i;
+ }
+ ++i;
+ }
+ /*
+ * Don't start sending this packet unless at least half of
+ * the channels are free. This gives much better TCP
+ * performance if we have a lot of channels.
+ */
+ if (nfree == 0 || nfree < navail / 2)
+ return 0; /* can't take now, leave it in xmit_pending */
+
+ /* Do protocol field compression */
+ p = skb->data;
+ len = skb->len;
+ if (*p == 0 && mp_protocol_compress) {
+ ++p;
+ --len;
+ }
+
+ totlen = len;
+ nbigger = len % nfree;
+
+ /* skip to the channel after the one we last used
+ and start at that one */
+ list = &ppp->channels;
+ for (i = 0; i < ppp->nxchan; ++i) {
+ list = list->next;
+ if (list == &ppp->channels) {
+ i = 0;
+ break;
+ }
+ }
+
+ /* create a fragment for each channel */
+ bits = B;
+ while (len > 0) {
+ list = list->next;
+ if (list == &ppp->channels) {
+ i = 0;
+ continue;
+ }
+ pch = list_entry(list, struct channel, clist);
+ ++i;
+ if (!pch->avail)
+ continue;
+
+ /*
+ * Skip this channel if it has a fragment pending already and
+ * we haven't given a fragment to all of the free channels.
+ */
+ if (pch->avail == 1) {
+ if (nfree > 0)
+ continue;
+ } else {
+ pch->avail = 1;
+ }
+
+ /* check the channel's mtu and whether it is still attached. */
+ spin_lock(&pch->downl);
+ if (pch->chan == NULL) {
+ /* can't use this channel, it's being deregistered */
+ if (pch->speed == 0)
+ nzero--;
+ else
+ totspeed -= pch->speed;
+
+ spin_unlock(&pch->downl);
+ pch->avail = 0;
+ totlen = len;
+ totfree--;
+ nfree--;
+ if (--navail == 0)
+ break;
+ continue;
+ }
+
+ /*
+ *if the channel speed is not set divide
+ *the packet evenly among the free channels;
+ *otherwise divide it according to the speed
+ *of the channel we are going to transmit on
+ */
+ flen = len;
+ if (nfree > 0) {
+ if (pch->speed == 0) {
+ flen = len/nfree;
+ if (nbigger > 0) {
+ flen++;
+ nbigger--;
+ }
+ } else {
+ flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
+ ((totspeed*totfree)/pch->speed)) - hdrlen;
+ if (nbigger > 0) {
+ flen += ((totfree - nzero)*pch->speed)/totspeed;
+ nbigger -= ((totfree - nzero)*pch->speed)/
+ totspeed;
+ }
+ }
+ nfree--;
+ }
+
+ /*
+ *check if we are on the last channel or
+ *we exceded the length of the data to
+ *fragment
+ */
+ if ((nfree <= 0) || (flen > len))
+ flen = len;
+ /*
+ *it is not worth to tx on slow channels:
+ *in that case from the resulting flen according to the
+ *above formula will be equal or less than zero.
+ *Skip the channel in this case
+ */
+ if (flen <= 0) {
+ pch->avail = 2;
+ spin_unlock(&pch->downl);
+ continue;
+ }
+
+ /*
+ * hdrlen includes the 2-byte PPP protocol field, but the
+ * MTU counts only the payload excluding the protocol field.
+ * (RFC1661 Section 2)
+ */
+ mtu = pch->chan->mtu - (hdrlen - 2);
+ if (mtu < 4)
+ mtu = 4;
+ if (flen > mtu)
+ flen = mtu;
+ if (flen == len)
+ bits |= E;
+ frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
+ if (!frag)
+ goto noskb;
+ q = skb_put(frag, flen + hdrlen);
+
+ /* make the MP header */
+ put_unaligned_be16(PPP_MP, q);
+ if (ppp->flags & SC_MP_XSHORTSEQ) {
+ q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
+ q[3] = ppp->nxseq;
+ } else {
+ q[2] = bits;
+ q[3] = ppp->nxseq >> 16;
+ q[4] = ppp->nxseq >> 8;
+ q[5] = ppp->nxseq;
+ }
+
+ memcpy(q + hdrlen, p, flen);
+
+ /* try to send it down the channel */
+ chan = pch->chan;
+ if (!skb_queue_empty(&pch->file.xq) ||
+ !chan->ops->start_xmit(chan, frag))
+ skb_queue_tail(&pch->file.xq, frag);
+ pch->had_frag = 1;
+ p += flen;
+ len -= flen;
+ ++ppp->nxseq;
+ bits = 0;
+ spin_unlock(&pch->downl);
+ }
+ ppp->nxchan = i;
+
+ return 1;
+
+ noskb:
+ spin_unlock(&pch->downl);
+ if (ppp->debug & 1)
+ netdev_err(ppp->dev, "PPP: no memory (fragment)\n");
+ ++ppp->dev->stats.tx_errors;
+ ++ppp->nxseq;
+ return 1; /* abandon the frame */
+}
+#endif /* CONFIG_PPP_MULTILINK */
+
+/* Try to send data out on a channel */
+static void __ppp_channel_push(struct channel *pch)
+{
+ struct sk_buff *skb;
+ struct ppp *ppp;
+
+ spin_lock(&pch->downl);
+ if (pch->chan) {
+ while (!skb_queue_empty(&pch->file.xq)) {
+ skb = skb_dequeue(&pch->file.xq);
+ if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
+ /* put the packet back and try again later */
+ skb_queue_head(&pch->file.xq, skb);
+ break;
+ }
+ }
+ } else {
+ /* channel got deregistered */
+ skb_queue_purge(&pch->file.xq);
+ }
+ spin_unlock(&pch->downl);
+ /* see if there is anything from the attached unit to be sent */
+ if (skb_queue_empty(&pch->file.xq)) {
+ ppp = pch->ppp;
+ if (ppp)
+ __ppp_xmit_process(ppp, NULL);
+ }
+}
+
+static void ppp_channel_push(struct channel *pch)
+{
+ read_lock_bh(&pch->upl);
+ if (pch->ppp) {
+ (*this_cpu_ptr(pch->ppp->xmit_recursion))++;
+ __ppp_channel_push(pch);
+ (*this_cpu_ptr(pch->ppp->xmit_recursion))--;
+ } else {
+ __ppp_channel_push(pch);
+ }
+ read_unlock_bh(&pch->upl);
+}
+
+/*
+ * Receive-side routines.
+ */
+
+struct ppp_mp_skb_parm {
+ u32 sequence;
+ u8 BEbits;
+};
+#define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb))
+
+static inline void
+ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
+{
+ ppp_recv_lock(ppp);
+ if (!ppp->closing)
+ ppp_receive_frame(ppp, skb, pch);
+ else
+ kfree_skb(skb);
+ ppp_recv_unlock(ppp);
+}
+
+void
+ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
+{
+ struct channel *pch = chan->ppp;
+ int proto;
+
+ if (!pch) {
+ kfree_skb(skb);
+ return;
+ }
+
+ read_lock_bh(&pch->upl);
+ if (!pskb_may_pull(skb, 2)) {
+ kfree_skb(skb);
+ if (pch->ppp) {
+ ++pch->ppp->dev->stats.rx_length_errors;
+ ppp_receive_error(pch->ppp);
+ }
+ goto done;
+ }
+
+ proto = PPP_PROTO(skb);
+ if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
+ /* put it on the channel queue */
+ skb_queue_tail(&pch->file.rq, skb);
+ /* drop old frames if queue too long */
+ while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
+ (skb = skb_dequeue(&pch->file.rq)))
+ kfree_skb(skb);
+ wake_up_interruptible(&pch->file.rwait);
+ } else {
+ ppp_do_recv(pch->ppp, skb, pch);
+ }
+
+done:
+ read_unlock_bh(&pch->upl);
+}
+
+/* Put a 0-length skb in the receive queue as an error indication */
+void
+ppp_input_error(struct ppp_channel *chan, int code)
+{
+ struct channel *pch = chan->ppp;
+ struct sk_buff *skb;
+
+ if (!pch)
+ return;
+
+ read_lock_bh(&pch->upl);
+ if (pch->ppp) {
+ skb = alloc_skb(0, GFP_ATOMIC);
+ if (skb) {
+ skb->len = 0; /* probably unnecessary */
+ skb->cb[0] = code;
+ ppp_do_recv(pch->ppp, skb, pch);
+ }
+ }
+ read_unlock_bh(&pch->upl);
+}
+
+/*
+ * We come in here to process a received frame.
+ * The receive side of the ppp unit is locked.
+ */
+static void
+ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
+{
+ /* note: a 0-length skb is used as an error indication */
+ if (skb->len > 0) {
+ skb_checksum_complete_unset(skb);
+#ifdef CONFIG_PPP_MULTILINK
+ /* XXX do channel-level decompression here */
+ if (PPP_PROTO(skb) == PPP_MP)
+ ppp_receive_mp_frame(ppp, skb, pch);
+ else
+#endif /* CONFIG_PPP_MULTILINK */
+ ppp_receive_nonmp_frame(ppp, skb);
+ } else {
+ kfree_skb(skb);
+ ppp_receive_error(ppp);
+ }
+}
+
+static void
+ppp_receive_error(struct ppp *ppp)
+{
+ ++ppp->dev->stats.rx_errors;
+ if (ppp->vj)
+ slhc_toss(ppp->vj);
+}
+
+static void
+ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
+{
+ struct sk_buff *ns;
+ int proto, len, npi;
+
+ /*
+ * Decompress the frame, if compressed.
+ * Note that some decompressors need to see uncompressed frames
+ * that come in as well as compressed frames.
+ */
+ if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
+ (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
+ skb = ppp_decompress_frame(ppp, skb);
+
+ if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
+ goto err;
+
+ proto = PPP_PROTO(skb);
+ switch (proto) {
+ case PPP_VJC_COMP:
+ /* decompress VJ compressed packets */
+ if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
+ goto err;
+
+ if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
+ /* copy to a new sk_buff with more tailroom */
+ ns = dev_alloc_skb(skb->len + 128);
+ if (!ns) {
+ netdev_err(ppp->dev, "PPP: no memory "
+ "(VJ decomp)\n");
+ goto err;
+ }
+ skb_reserve(ns, 2);
+ skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
+ consume_skb(skb);
+ skb = ns;
+ }
+ else
+ skb->ip_summed = CHECKSUM_NONE;
+
+ len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
+ if (len <= 0) {
+ netdev_printk(KERN_DEBUG, ppp->dev,
+ "PPP: VJ decompression error\n");
+ goto err;
+ }
+ len += 2;
+ if (len > skb->len)
+ skb_put(skb, len - skb->len);
+ else if (len < skb->len)
+ skb_trim(skb, len);
+ proto = PPP_IP;
+ break;
+
+ case PPP_VJC_UNCOMP:
+ if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
+ goto err;
+
+ /* Until we fix the decompressor need to make sure
+ * data portion is linear.
+ */
+ if (!pskb_may_pull(skb, skb->len))
+ goto err;
+
+ if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
+ netdev_err(ppp->dev, "PPP: VJ uncompressed error\n");
+ goto err;
+ }
+ proto = PPP_IP;
+ break;
+
+ case PPP_CCP:
+ ppp_ccp_peek(ppp, skb, 1);
+ break;
+ }
+
+ ++ppp->stats64.rx_packets;
+ ppp->stats64.rx_bytes += skb->len - 2;
+
+ npi = proto_to_npindex(proto);
+ if (npi < 0) {
+ /* control or unknown frame - pass it to pppd */
+ skb_queue_tail(&ppp->file.rq, skb);
+ /* limit queue length by dropping old frames */
+ while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
+ (skb = skb_dequeue(&ppp->file.rq)))
+ kfree_skb(skb);
+ /* wake up any process polling or blocking on read */
+ wake_up_interruptible(&ppp->file.rwait);
+
+ } else {
+ /* network protocol frame - give it to the kernel */
+
+#ifdef CONFIG_PPP_FILTER
+ /* check if the packet passes the pass and active filters */
+ /* the filter instructions are constructed assuming
+ a four-byte PPP header on each packet */
+ if (ppp->pass_filter || ppp->active_filter) {
+ if (skb_unclone(skb, GFP_ATOMIC))
+ goto err;
+
+ *(u8 *)skb_push(skb, 2) = 0;
+ if (ppp->pass_filter &&
+ BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
+ if (ppp->debug & 1)
+ netdev_printk(KERN_DEBUG, ppp->dev,
+ "PPP: inbound frame "
+ "not passed\n");
+ kfree_skb(skb);
+ return;
+ }
+ if (!(ppp->active_filter &&
+ BPF_PROG_RUN(ppp->active_filter, skb) == 0))
+ ppp->last_recv = jiffies;
+ __skb_pull(skb, 2);
+ } else
+#endif /* CONFIG_PPP_FILTER */
+ ppp->last_recv = jiffies;
+
+ if ((ppp->dev->flags & IFF_UP) == 0 ||
+ ppp->npmode[npi] != NPMODE_PASS) {
+ kfree_skb(skb);
+ } else {
+ /* chop off protocol */
+ skb_pull_rcsum(skb, 2);
+ skb->dev = ppp->dev;
+ skb->protocol = htons(npindex_to_ethertype[npi]);
+ skb_reset_mac_header(skb);
+ skb_scrub_packet(skb, !net_eq(ppp->ppp_net,
+ dev_net(ppp->dev)));
+ netif_rx(skb);
+ }
+ }
+ return;
+
+ err:
+ kfree_skb(skb);
+ ppp_receive_error(ppp);
+}
+
+static struct sk_buff *
+ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
+{
+ int proto = PPP_PROTO(skb);
+ struct sk_buff *ns;
+ int len;
+
+ /* Until we fix all the decompressor's need to make sure
+ * data portion is linear.
+ */
+ if (!pskb_may_pull(skb, skb->len))
+ goto err;
+
+ if (proto == PPP_COMP) {
+ int obuff_size;
+
+ switch(ppp->rcomp->compress_proto) {
+ case CI_MPPE:
+ obuff_size = ppp->mru + PPP_HDRLEN + 1;
+ break;
+ default:
+ obuff_size = ppp->mru + PPP_HDRLEN;
+ break;
+ }
+
+ ns = dev_alloc_skb(obuff_size);
+ if (!ns) {
+ netdev_err(ppp->dev, "ppp_decompress_frame: "
+ "no memory\n");
+ goto err;
+ }
+ /* the decompressor still expects the A/C bytes in the hdr */
+ len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
+ skb->len + 2, ns->data, obuff_size);
+ if (len < 0) {
+ /* Pass the compressed frame to pppd as an
+ error indication. */
+ if (len == DECOMP_FATALERROR)
+ ppp->rstate |= SC_DC_FERROR;
+ kfree_skb(ns);
+ goto err;
+ }
+
+ consume_skb(skb);
+ skb = ns;
+ skb_put(skb, len);
+ skb_pull(skb, 2); /* pull off the A/C bytes */
+
+ } else {
+ /* Uncompressed frame - pass to decompressor so it
+ can update its dictionary if necessary. */
+ if (ppp->rcomp->incomp)
+ ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
+ skb->len + 2);
+ }
+
+ return skb;
+
+ err:
+ ppp->rstate |= SC_DC_ERROR;
+ ppp_receive_error(ppp);
+ return skb;
+}
+
+#ifdef CONFIG_PPP_MULTILINK
+/*
+ * Receive a multilink frame.
+ * We put it on the reconstruction queue and then pull off
+ * as many completed frames as we can.
+ */
+static void
+ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
+{
+ u32 mask, seq;
+ struct channel *ch;
+ int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
+
+ if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
+ goto err; /* no good, throw it away */
+
+ /* Decode sequence number and begin/end bits */
+ if (ppp->flags & SC_MP_SHORTSEQ) {
+ seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
+ mask = 0xfff;
+ } else {
+ seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
+ mask = 0xffffff;
+ }
+ PPP_MP_CB(skb)->BEbits = skb->data[2];
+ skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
+
+ /*
+ * Do protocol ID decompression on the first fragment of each packet.
+ */
+ if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1))
+ *(u8 *)skb_push(skb, 1) = 0;
+
+ /*
+ * Expand sequence number to 32 bits, making it as close
+ * as possible to ppp->minseq.
+ */
+ seq |= ppp->minseq & ~mask;
+ if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
+ seq += mask + 1;
+ else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
+ seq -= mask + 1; /* should never happen */
+ PPP_MP_CB(skb)->sequence = seq;
+ pch->lastseq = seq;
+
+ /*
+ * If this packet comes before the next one we were expecting,
+ * drop it.
+ */
+ if (seq_before(seq, ppp->nextseq)) {
+ kfree_skb(skb);
+ ++ppp->dev->stats.rx_dropped;
+ ppp_receive_error(ppp);
+ return;
+ }
+
+ /*
+ * Reevaluate minseq, the minimum over all channels of the
+ * last sequence number received on each channel. Because of
+ * the increasing sequence number rule, we know that any fragment
+ * before `minseq' which hasn't arrived is never going to arrive.
+ * The list of channels can't change because we have the receive
+ * side of the ppp unit locked.
+ */
+ list_for_each_entry(ch, &ppp->channels, clist) {
+ if (seq_before(ch->lastseq, seq))
+ seq = ch->lastseq;
+ }
+ if (seq_before(ppp->minseq, seq))
+ ppp->minseq = seq;
+
+ /* Put the fragment on the reconstruction queue */
+ ppp_mp_insert(ppp, skb);
+
+ /* If the queue is getting long, don't wait any longer for packets
+ before the start of the queue. */
+ if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
+ struct sk_buff *mskb = skb_peek(&ppp->mrq);
+ if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence))
+ ppp->minseq = PPP_MP_CB(mskb)->sequence;
+ }
+
+ /* Pull completed packets off the queue and receive them. */
+ while ((skb = ppp_mp_reconstruct(ppp))) {
+ if (pskb_may_pull(skb, 2))
+ ppp_receive_nonmp_frame(ppp, skb);
+ else {
+ ++ppp->dev->stats.rx_length_errors;
+ kfree_skb(skb);
+ ppp_receive_error(ppp);
+ }
+ }
+
+ return;
+
+ err:
+ kfree_skb(skb);
+ ppp_receive_error(ppp);
+}
+
+/*
+ * Insert a fragment on the MP reconstruction queue.
+ * The queue is ordered by increasing sequence number.
+ */
+static void
+ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
+{
+ struct sk_buff *p;
+ struct sk_buff_head *list = &ppp->mrq;
+ u32 seq = PPP_MP_CB(skb)->sequence;
+
+ /* N.B. we don't need to lock the list lock because we have the
+ ppp unit receive-side lock. */
+ skb_queue_walk(list, p) {
+ if (seq_before(seq, PPP_MP_CB(p)->sequence))
+ break;
+ }
+ __skb_queue_before(list, p, skb);
+}
+
+/*
+ * Reconstruct a packet from the MP fragment queue.
+ * We go through increasing sequence numbers until we find a
+ * complete packet, or we get to the sequence number for a fragment
+ * which hasn't arrived but might still do so.
+ */
+static struct sk_buff *
+ppp_mp_reconstruct(struct ppp *ppp)
+{
+ u32 seq = ppp->nextseq;
+ u32 minseq = ppp->minseq;
+ struct sk_buff_head *list = &ppp->mrq;
+ struct sk_buff *p, *tmp;
+ struct sk_buff *head, *tail;
+ struct sk_buff *skb = NULL;
+ int lost = 0, len = 0;
+
+ if (ppp->mrru == 0) /* do nothing until mrru is set */
+ return NULL;
+ head = list->next;
+ tail = NULL;
+ skb_queue_walk_safe(list, p, tmp) {
+ again:
+ if (seq_before(PPP_MP_CB(p)->sequence, seq)) {
+ /* this can't happen, anyway ignore the skb */
+ netdev_err(ppp->dev, "ppp_mp_reconstruct bad "
+ "seq %u < %u\n",
+ PPP_MP_CB(p)->sequence, seq);
+ __skb_unlink(p, list);
+ kfree_skb(p);
+ continue;
+ }
+ if (PPP_MP_CB(p)->sequence != seq) {
+ u32 oldseq;
+ /* Fragment `seq' is missing. If it is after
+ minseq, it might arrive later, so stop here. */
+ if (seq_after(seq, minseq))
+ break;
+ /* Fragment `seq' is lost, keep going. */
+ lost = 1;
+ oldseq = seq;
+ seq = seq_before(minseq, PPP_MP_CB(p)->sequence)?
+ minseq + 1: PPP_MP_CB(p)->sequence;
+
+ if (ppp->debug & 1)
+ netdev_printk(KERN_DEBUG, ppp->dev,
+ "lost frag %u..%u\n",
+ oldseq, seq-1);
+
+ goto again;
+ }
+
+ /*
+ * At this point we know that all the fragments from
+ * ppp->nextseq to seq are either present or lost.
+ * Also, there are no complete packets in the queue
+ * that have no missing fragments and end before this
+ * fragment.
+ */
+
+ /* B bit set indicates this fragment starts a packet */
+ if (PPP_MP_CB(p)->BEbits & B) {
+ head = p;
+ lost = 0;
+ len = 0;
+ }
+
+ len += p->len;
+
+ /* Got a complete packet yet? */
+ if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) &&
+ (PPP_MP_CB(head)->BEbits & B)) {
+ if (len > ppp->mrru + 2) {
+ ++ppp->dev->stats.rx_length_errors;
+ netdev_printk(KERN_DEBUG, ppp->dev,
+ "PPP: reconstructed packet"
+ " is too long (%d)\n", len);
+ } else {
+ tail = p;
+ break;
+ }
+ ppp->nextseq = seq + 1;
+ }
+
+ /*
+ * If this is the ending fragment of a packet,
+ * and we haven't found a complete valid packet yet,
+ * we can discard up to and including this fragment.
+ */
+ if (PPP_MP_CB(p)->BEbits & E) {
+ struct sk_buff *tmp2;
+
+ skb_queue_reverse_walk_from_safe(list, p, tmp2) {
+ if (ppp->debug & 1)
+ netdev_printk(KERN_DEBUG, ppp->dev,
+ "discarding frag %u\n",
+ PPP_MP_CB(p)->sequence);
+ __skb_unlink(p, list);
+ kfree_skb(p);
+ }
+ head = skb_peek(list);
+ if (!head)
+ break;
+ }
+ ++seq;
+ }
+
+ /* If we have a complete packet, copy it all into one skb. */
+ if (tail != NULL) {
+ /* If we have discarded any fragments,
+ signal a receive error. */
+ if (PPP_MP_CB(head)->sequence != ppp->nextseq) {
+ skb_queue_walk_safe(list, p, tmp) {
+ if (p == head)
+ break;
+ if (ppp->debug & 1)
+ netdev_printk(KERN_DEBUG, ppp->dev,
+ "discarding frag %u\n",
+ PPP_MP_CB(p)->sequence);
+ __skb_unlink(p, list);
+ kfree_skb(p);
+ }
+
+ if (ppp->debug & 1)
+ netdev_printk(KERN_DEBUG, ppp->dev,
+ " missed pkts %u..%u\n",
+ ppp->nextseq,
+ PPP_MP_CB(head)->sequence-1);
+ ++ppp->dev->stats.rx_dropped;
+ ppp_receive_error(ppp);
+ }
+
+ skb = head;
+ if (head != tail) {
+ struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list;
+ p = skb_queue_next(list, head);
+ __skb_unlink(skb, list);
+ skb_queue_walk_from_safe(list, p, tmp) {
+ __skb_unlink(p, list);
+ *fragpp = p;
+ p->next = NULL;
+ fragpp = &p->next;
+
+ skb->len += p->len;
+ skb->data_len += p->len;
+ skb->truesize += p->truesize;
+
+ if (p == tail)
+ break;
+ }
+ } else {
+ __skb_unlink(skb, list);
+ }
+
+ ppp->nextseq = PPP_MP_CB(tail)->sequence + 1;
+ }
+
+ return skb;
+}
+#endif /* CONFIG_PPP_MULTILINK */
+
+/*
+ * Channel interface.
+ */
+
+/* Create a new, unattached ppp channel. */
+int ppp_register_channel(struct ppp_channel *chan)
+{
+ return ppp_register_net_channel(current->nsproxy->net_ns, chan);
+}
+
+/* Create a new, unattached ppp channel for specified net. */
+int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
+{
+ struct channel *pch;
+ struct ppp_net *pn;
+
+ pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
+ if (!pch)
+ return -ENOMEM;
+
+ pn = ppp_pernet(net);
+
+ pch->ppp = NULL;
+ pch->chan = chan;
+ pch->chan_net = get_net(net);
+ chan->ppp = pch;
+ init_ppp_file(&pch->file, CHANNEL);
+ pch->file.hdrlen = chan->hdrlen;
+#ifdef CONFIG_PPP_MULTILINK
+ pch->lastseq = -1;
+#endif /* CONFIG_PPP_MULTILINK */
+ init_rwsem(&pch->chan_sem);
+ spin_lock_init(&pch->downl);
+ rwlock_init(&pch->upl);
+
+ spin_lock_bh(&pn->all_channels_lock);
+ pch->file.index = ++pn->last_channel_index;
+ list_add(&pch->list, &pn->new_channels);
+ atomic_inc(&channel_count);
+ spin_unlock_bh(&pn->all_channels_lock);
+
+ return 0;
+}
+
+/*
+ * Return the index of a channel.
+ */
+int ppp_channel_index(struct ppp_channel *chan)
+{
+ struct channel *pch = chan->ppp;
+
+ if (pch)
+ return pch->file.index;
+ return -1;
+}
+
+/*
+ * Return the PPP unit number to which a channel is connected.
+ */
+int ppp_unit_number(struct ppp_channel *chan)
+{
+ struct channel *pch = chan->ppp;
+ int unit = -1;
+
+ if (pch) {
+ read_lock_bh(&pch->upl);
+ if (pch->ppp)
+ unit = pch->ppp->file.index;
+ read_unlock_bh(&pch->upl);
+ }
+ return unit;
+}
+
+/*
+ * Return the PPP device interface name of a channel.
+ */
+char *ppp_dev_name(struct ppp_channel *chan)
+{
+ struct channel *pch = chan->ppp;
+ char *name = NULL;
+
+ if (pch) {
+ read_lock_bh(&pch->upl);
+ if (pch->ppp && pch->ppp->dev)
+ name = pch->ppp->dev->name;
+ read_unlock_bh(&pch->upl);
+ }
+ return name;
+}
+
+
+/*
+ * Disconnect a channel from the generic layer.
+ * This must be called in process context.
+ */
+void
+ppp_unregister_channel(struct ppp_channel *chan)
+{
+ struct channel *pch = chan->ppp;
+ struct ppp_net *pn;
+
+ if (!pch)
+ return; /* should never happen */
+
+ chan->ppp = NULL;
+
+ /*
+ * This ensures that we have returned from any calls into the
+ * the channel's start_xmit or ioctl routine before we proceed.
+ */
+ down_write(&pch->chan_sem);
+ spin_lock_bh(&pch->downl);
+ pch->chan = NULL;
+ spin_unlock_bh(&pch->downl);
+ up_write(&pch->chan_sem);
+ ppp_disconnect_channel(pch);
+
+ pn = ppp_pernet(pch->chan_net);
+ spin_lock_bh(&pn->all_channels_lock);
+ list_del(&pch->list);
+ spin_unlock_bh(&pn->all_channels_lock);
+
+ pch->file.dead = 1;
+ wake_up_interruptible(&pch->file.rwait);
+ if (refcount_dec_and_test(&pch->file.refcnt))
+ ppp_destroy_channel(pch);
+}
+
+/*
+ * Callback from a channel when it can accept more to transmit.
+ * This should be called at BH/softirq level, not interrupt level.
+ */
+void
+ppp_output_wakeup(struct ppp_channel *chan)
+{
+ struct channel *pch = chan->ppp;
+
+ if (!pch)
+ return;
+ ppp_channel_push(pch);
+}
+
+/*
+ * Compression control.
+ */
+
+/* Process the PPPIOCSCOMPRESS ioctl. */
+static int
+ppp_set_compress(struct ppp *ppp, unsigned long arg)
+{
+ int err;
+ struct compressor *cp, *ocomp;
+ struct ppp_option_data data;
+ void *state, *ostate;
+ unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
+
+ err = -EFAULT;
+ if (copy_from_user(&data, (void __user *) arg, sizeof(data)))
+ goto out;
+ if (data.length > CCP_MAX_OPTION_LENGTH)
+ goto out;
+ if (copy_from_user(ccp_option, (void __user *) data.ptr, data.length))
+ goto out;
+
+ err = -EINVAL;
+ if (data.length < 2 || ccp_option[1] < 2 || ccp_option[1] > data.length)
+ goto out;
+
+ cp = try_then_request_module(
+ find_compressor(ccp_option[0]),
+ "ppp-compress-%d", ccp_option[0]);
+ if (!cp)
+ goto out;
+
+ err = -ENOBUFS;
+ if (data.transmit) {
+ state = cp->comp_alloc(ccp_option, data.length);
+ if (state) {
+ ppp_xmit_lock(ppp);
+ ppp->xstate &= ~SC_COMP_RUN;
+ ocomp = ppp->xcomp;
+ ostate = ppp->xc_state;
+ ppp->xcomp = cp;
+ ppp->xc_state = state;
+ ppp_xmit_unlock(ppp);
+ if (ostate) {
+ ocomp->comp_free(ostate);
+ module_put(ocomp->owner);
+ }
+ err = 0;
+ } else
+ module_put(cp->owner);
+
+ } else {
+ state = cp->decomp_alloc(ccp_option, data.length);
+ if (state) {
+ ppp_recv_lock(ppp);
+ ppp->rstate &= ~SC_DECOMP_RUN;
+ ocomp = ppp->rcomp;
+ ostate = ppp->rc_state;
+ ppp->rcomp = cp;
+ ppp->rc_state = state;
+ ppp_recv_unlock(ppp);
+ if (ostate) {
+ ocomp->decomp_free(ostate);
+ module_put(ocomp->owner);
+ }
+ err = 0;
+ } else
+ module_put(cp->owner);
+ }
+
+ out:
+ return err;
+}
+
+/*
+ * Look at a CCP packet and update our state accordingly.
+ * We assume the caller has the xmit or recv path locked.
+ */
+static void
+ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
+{
+ unsigned char *dp;
+ int len;
+
+ if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
+ return; /* no header */
+ dp = skb->data + 2;
+
+ switch (CCP_CODE(dp)) {
+ case CCP_CONFREQ:
+
+ /* A ConfReq starts negotiation of compression
+ * in one direction of transmission,
+ * and hence brings it down...but which way?
+ *
+ * Remember:
+ * A ConfReq indicates what the sender would like to receive
+ */
+ if(inbound)
+ /* He is proposing what I should send */
+ ppp->xstate &= ~SC_COMP_RUN;
+ else
+ /* I am proposing to what he should send */
+ ppp->rstate &= ~SC_DECOMP_RUN;
+
+ break;
+
+ case CCP_TERMREQ:
+ case CCP_TERMACK:
+ /*
+ * CCP is going down, both directions of transmission
+ */
+ ppp->rstate &= ~SC_DECOMP_RUN;
+ ppp->xstate &= ~SC_COMP_RUN;
+ break;
+
+ case CCP_CONFACK:
+ if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
+ break;
+ len = CCP_LENGTH(dp);
+ if (!pskb_may_pull(skb, len + 2))
+ return; /* too short */
+ dp += CCP_HDRLEN;
+ len -= CCP_HDRLEN;
+ if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
+ break;
+ if (inbound) {
+ /* we will start receiving compressed packets */
+ if (!ppp->rc_state)
+ break;
+ if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
+ ppp->file.index, 0, ppp->mru, ppp->debug)) {
+ ppp->rstate |= SC_DECOMP_RUN;
+ ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
+ }
+ } else {
+ /* we will soon start sending compressed packets */
+ if (!ppp->xc_state)
+ break;
+ if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
+ ppp->file.index, 0, ppp->debug))
+ ppp->xstate |= SC_COMP_RUN;
+ }
+ break;
+
+ case CCP_RESETACK:
+ /* reset the [de]compressor */
+ if ((ppp->flags & SC_CCP_UP) == 0)
+ break;
+ if (inbound) {
+ if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
+ ppp->rcomp->decomp_reset(ppp->rc_state);
+ ppp->rstate &= ~SC_DC_ERROR;
+ }
+ } else {
+ if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
+ ppp->xcomp->comp_reset(ppp->xc_state);
+ }
+ break;
+ }
+}
+
+/* Free up compression resources. */
+static void
+ppp_ccp_closed(struct ppp *ppp)
+{
+ void *xstate, *rstate;
+ struct compressor *xcomp, *rcomp;
+
+ ppp_lock(ppp);
+ ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
+ ppp->xstate = 0;
+ xcomp = ppp->xcomp;
+ xstate = ppp->xc_state;
+ ppp->xc_state = NULL;
+ ppp->rstate = 0;
+ rcomp = ppp->rcomp;
+ rstate = ppp->rc_state;
+ ppp->rc_state = NULL;
+ ppp_unlock(ppp);
+
+ if (xstate) {
+ xcomp->comp_free(xstate);
+ module_put(xcomp->owner);
+ }
+ if (rstate) {
+ rcomp->decomp_free(rstate);
+ module_put(rcomp->owner);
+ }
+}
+
+/* List of compressors. */
+static LIST_HEAD(compressor_list);
+static DEFINE_SPINLOCK(compressor_list_lock);
+
+struct compressor_entry {
+ struct list_head list;
+ struct compressor *comp;
+};
+
+static struct compressor_entry *
+find_comp_entry(int proto)
+{
+ struct compressor_entry *ce;
+
+ list_for_each_entry(ce, &compressor_list, list) {
+ if (ce->comp->compress_proto == proto)
+ return ce;
+ }
+ return NULL;
+}
+
+/* Register a compressor */
+int
+ppp_register_compressor(struct compressor *cp)
+{
+ struct compressor_entry *ce;
+ int ret;
+ spin_lock(&compressor_list_lock);
+ ret = -EEXIST;
+ if (find_comp_entry(cp->compress_proto))
+ goto out;
+ ret = -ENOMEM;
+ ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
+ if (!ce)
+ goto out;
+ ret = 0;
+ ce->comp = cp;
+ list_add(&ce->list, &compressor_list);
+ out:
+ spin_unlock(&compressor_list_lock);
+ return ret;
+}
+
+/* Unregister a compressor */
+void
+ppp_unregister_compressor(struct compressor *cp)
+{
+ struct compressor_entry *ce;
+
+ spin_lock(&compressor_list_lock);
+ ce = find_comp_entry(cp->compress_proto);
+ if (ce && ce->comp == cp) {
+ list_del(&ce->list);
+ kfree(ce);
+ }
+ spin_unlock(&compressor_list_lock);
+}
+
+/* Find a compressor. */
+static struct compressor *
+find_compressor(int type)
+{
+ struct compressor_entry *ce;
+ struct compressor *cp = NULL;
+
+ spin_lock(&compressor_list_lock);
+ ce = find_comp_entry(type);
+ if (ce) {
+ cp = ce->comp;
+ if (!try_module_get(cp->owner))
+ cp = NULL;
+ }
+ spin_unlock(&compressor_list_lock);
+ return cp;
+}
+
+/*
+ * Miscelleneous stuff.
+ */
+
+static void
+ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
+{
+ struct slcompress *vj = ppp->vj;
+
+ memset(st, 0, sizeof(*st));
+ st->p.ppp_ipackets = ppp->stats64.rx_packets;
+ st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
+ st->p.ppp_ibytes = ppp->stats64.rx_bytes;
+ st->p.ppp_opackets = ppp->stats64.tx_packets;
+ st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
+ st->p.ppp_obytes = ppp->stats64.tx_bytes;
+ if (!vj)
+ return;
+ st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
+ st->vj.vjs_compressed = vj->sls_o_compressed;
+ st->vj.vjs_searches = vj->sls_o_searches;
+ st->vj.vjs_misses = vj->sls_o_misses;
+ st->vj.vjs_errorin = vj->sls_i_error;
+ st->vj.vjs_tossed = vj->sls_i_tossed;
+ st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
+ st->vj.vjs_compressedin = vj->sls_i_compressed;
+}
+
+/*
+ * Stuff for handling the lists of ppp units and channels
+ * and for initialization.
+ */
+
+/*
+ * Create a new ppp interface unit. Fails if it can't allocate memory
+ * or if there is already a unit with the requested number.
+ * unit == -1 means allocate a new number.
+ */
+static int ppp_create_interface(struct net *net, struct file *file, int *unit)
+{
+ struct ppp_config conf = {
+ .file = file,
+ .unit = *unit,
+ .ifname_is_set = false,
+ };
+ struct net_device *dev;
+ struct ppp *ppp;
+ int err;
+
+ dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_ENUM, ppp_setup);
+ if (!dev) {
+ err = -ENOMEM;
+ goto err;
+ }
+ dev_net_set(dev, net);
+ dev->rtnl_link_ops = &ppp_link_ops;
+
+ rtnl_lock();
+
+ err = ppp_dev_configure(net, dev, &conf);
+ if (err < 0)
+ goto err_dev;
+ ppp = netdev_priv(dev);
+ *unit = ppp->file.index;
+
+ rtnl_unlock();
+
+ return 0;
+
+err_dev:
+ rtnl_unlock();
+ free_netdev(dev);
+err:
+ return err;
+}
+
+/*
+ * Initialize a ppp_file structure.
+ */
+static void
+init_ppp_file(struct ppp_file *pf, int kind)
+{
+ pf->kind = kind;
+ skb_queue_head_init(&pf->xq);
+ skb_queue_head_init(&pf->rq);
+ refcount_set(&pf->refcnt, 1);
+ init_waitqueue_head(&pf->rwait);
+}
+
+/*
+ * Free the memory used by a ppp unit. This is only called once
+ * there are no channels connected to the unit and no file structs
+ * that reference the unit.
+ */
+static void ppp_destroy_interface(struct ppp *ppp)
+{
+ atomic_dec(&ppp_unit_count);
+
+ if (!ppp->file.dead || ppp->n_channels) {
+ /* "can't happen" */
+ netdev_err(ppp->dev, "ppp: destroying ppp struct %p "
+ "but dead=%d n_channels=%d !\n",
+ ppp, ppp->file.dead, ppp->n_channels);
+ return;
+ }
+
+ ppp_ccp_closed(ppp);
+ if (ppp->vj) {
+ slhc_free(ppp->vj);
+ ppp->vj = NULL;
+ }
+ skb_queue_purge(&ppp->file.xq);
+ skb_queue_purge(&ppp->file.rq);
+#ifdef CONFIG_PPP_MULTILINK
+ skb_queue_purge(&ppp->mrq);
+#endif /* CONFIG_PPP_MULTILINK */
+#ifdef CONFIG_PPP_FILTER
+ if (ppp->pass_filter) {
+ bpf_prog_destroy(ppp->pass_filter);
+ ppp->pass_filter = NULL;
+ }
+
+ if (ppp->active_filter) {
+ bpf_prog_destroy(ppp->active_filter);
+ ppp->active_filter = NULL;
+ }
+#endif /* CONFIG_PPP_FILTER */
+
+ kfree_skb(ppp->xmit_pending);
+ free_percpu(ppp->xmit_recursion);
+
+ free_netdev(ppp->dev);
+}
+
+/*
+ * Locate an existing ppp unit.
+ * The caller should have locked the all_ppp_mutex.
+ */
+static struct ppp *
+ppp_find_unit(struct ppp_net *pn, int unit)
+{
+ return unit_find(&pn->units_idr, unit);
+}
+
+/*
+ * Locate an existing ppp channel.
+ * The caller should have locked the all_channels_lock.
+ * First we look in the new_channels list, then in the
+ * all_channels list. If found in the new_channels list,
+ * we move it to the all_channels list. This is for speed
+ * when we have a lot of channels in use.
+ */
+static struct channel *
+ppp_find_channel(struct ppp_net *pn, int unit)
+{
+ struct channel *pch;
+
+ list_for_each_entry(pch, &pn->new_channels, list) {
+ if (pch->file.index == unit) {
+ list_move(&pch->list, &pn->all_channels);
+ return pch;
+ }
+ }
+
+ list_for_each_entry(pch, &pn->all_channels, list) {
+ if (pch->file.index == unit)
+ return pch;
+ }
+
+ return NULL;
+}
+
+/*
+ * Connect a PPP channel to a PPP interface unit.
+ */
+static int
+ppp_connect_channel(struct channel *pch, int unit)
+{
+ struct ppp *ppp;
+ struct ppp_net *pn;
+ int ret = -ENXIO;
+ int hdrlen;
+
+ pn = ppp_pernet(pch->chan_net);
+
+ mutex_lock(&pn->all_ppp_mutex);
+ ppp = ppp_find_unit(pn, unit);
+ if (!ppp)
+ goto out;
+ write_lock_bh(&pch->upl);
+ ret = -EINVAL;
+ if (pch->ppp)
+ goto outl;
+
+ ppp_lock(ppp);
+ spin_lock_bh(&pch->downl);
+ if (!pch->chan) {
+ /* Don't connect unregistered channels */
+ spin_unlock_bh(&pch->downl);
+ ppp_unlock(ppp);
+ ret = -ENOTCONN;
+ goto outl;
+ }
+ spin_unlock_bh(&pch->downl);
+ if (pch->file.hdrlen > ppp->file.hdrlen)
+ ppp->file.hdrlen = pch->file.hdrlen;
+ hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
+ if (hdrlen > ppp->dev->hard_header_len)
+ ppp->dev->hard_header_len = hdrlen;
+ list_add_tail(&pch->clist, &ppp->channels);
+ ++ppp->n_channels;
+ pch->ppp = ppp;
+ refcount_inc(&ppp->file.refcnt);
+ ppp_unlock(ppp);
+ ret = 0;
+
+ outl:
+ write_unlock_bh(&pch->upl);
+ out:
+ mutex_unlock(&pn->all_ppp_mutex);
+ return ret;
+}
+
+/*
+ * Disconnect a channel from its ppp unit.
+ */
+static int
+ppp_disconnect_channel(struct channel *pch)
+{
+ struct ppp *ppp;
+ int err = -EINVAL;
+
+ write_lock_bh(&pch->upl);
+ ppp = pch->ppp;
+ pch->ppp = NULL;
+ write_unlock_bh(&pch->upl);
+ if (ppp) {
+ /* remove it from the ppp unit's list */
+ ppp_lock(ppp);
+ list_del(&pch->clist);
+ if (--ppp->n_channels == 0)
+ wake_up_interruptible(&ppp->file.rwait);
+ ppp_unlock(ppp);
+ if (refcount_dec_and_test(&ppp->file.refcnt))
+ ppp_destroy_interface(ppp);
+ err = 0;
+ }
+ return err;
+}
+
+/*
+ * Free up the resources used by a ppp channel.
+ */
+static void ppp_destroy_channel(struct channel *pch)
+{
+ put_net(pch->chan_net);
+ pch->chan_net = NULL;
+
+ atomic_dec(&channel_count);
+
+ if (!pch->file.dead) {
+ /* "can't happen" */
+ pr_err("ppp: destroying undead channel %p !\n", pch);
+ return;
+ }
+ skb_queue_purge(&pch->file.xq);
+ skb_queue_purge(&pch->file.rq);
+ kfree(pch);
+}
+
+static void __exit ppp_cleanup(void)
+{
+ /* should never happen */
+ if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
+ pr_err("PPP: removing module but units remain!\n");
+ rtnl_link_unregister(&ppp_link_ops);
+ unregister_chrdev(PPP_MAJOR, "ppp");
+ device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
+ class_destroy(ppp_class);
+ unregister_pernet_device(&ppp_net_ops);
+}
+
+/*
+ * Units handling. Caller must protect concurrent access
+ * by holding all_ppp_mutex
+ */
+
+/* associate pointer with specified number */
+static int unit_set(struct idr *p, void *ptr, int n)
+{
+ int unit;
+
+ unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL);
+ if (unit == -ENOSPC)
+ unit = -EINVAL;
+ return unit;
+}
+
+/* get new free unit number and associate pointer with it */
+static int unit_get(struct idr *p, void *ptr)
+{
+ return idr_alloc(p, ptr, 0, 0, GFP_KERNEL);
+}
+
+/* put unit number back to a pool */
+static void unit_put(struct idr *p, int n)
+{
+ idr_remove(p, n);
+}
+
+/* get pointer associated with the number */
+static void *unit_find(struct idr *p, int n)
+{
+ return idr_find(p, n);
+}
+
+/* Module/initialization stuff */
+
+module_init(ppp_init);
+module_exit(ppp_cleanup);
+
+EXPORT_SYMBOL(ppp_register_net_channel);
+EXPORT_SYMBOL(ppp_register_channel);
+EXPORT_SYMBOL(ppp_unregister_channel);
+EXPORT_SYMBOL(ppp_channel_index);
+EXPORT_SYMBOL(ppp_unit_number);
+EXPORT_SYMBOL(ppp_dev_name);
+EXPORT_SYMBOL(ppp_input);
+EXPORT_SYMBOL(ppp_input_error);
+EXPORT_SYMBOL(ppp_output_wakeup);
+EXPORT_SYMBOL(ppp_register_compressor);
+EXPORT_SYMBOL(ppp_unregister_compressor);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
+MODULE_ALIAS_RTNL_LINK("ppp");
+MODULE_ALIAS("devname:ppp");